Sensitive fuse



June 14, 1949. R. L. GRAUMANN SENSITIVE FUSE Filed Aug. ,5, 1940 INVENTOR mandl.gmumamv W Anemia;

Patented June 14, 1949 (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

This invention relates to a sensitive fuze for use in exploding the bursting charge of rotating or, spinning projectiles and more particularly to a fuze adapted for use with the spinning type of bomb, certain elements of the fuze being operable by centrifugal force to change the fuze from unarmed condition to armed condition.

Among the several objects of this invention are:

To provide a highly sensitive fuze that is never-' theless safe to handle;

To provide firing means that will be of suifi ciently rugged construction to detonate the bomb when the fuze is armed but will yield and notdetonate the bomb unless the fuze has been armed by rotation;

To provide a fuze with a minimum number of parts and a maximum simplicity of construction; and

To eliminate the necessity for an air-driven propeller on a projectile to arm the fuze.

In the drawings:

Fig. l. is a side elevation of a bomb provided with a fuze according to the present invention, with certain parts in section;'

Fig. 2 is an axial section of the fuze in the unarmed condition substantially on the line 2-2, Fig. 3;

Fig. 3 is a transverse section of the fuze on the line 33, Fig. 2; and

Fig. 4 is a fragmentary view similar to Fig. 2 but with the fuze elements in the armed condition.

As is shown in Fig. 1, my present invention is primarily designed for use with a bomb such as 5 particularly adapted tobe launched from aircraft and having tail vanes B that are given an angular pitch to cause the bomb to spin about its longitudinal axis when falling, as is indicated by the dot and dash line i on the body of bomb 5. The pitch of the vanes 5 may be about 5, which case it requires several hundred feet of fall to arm the fuze 8. However, if it is desired that the fuze should be armed in a distance of a hundred feet or so the vanes 5 may be given a pitch of The fuze 3 comprises two members 9 and it that constitute the body thereof and which, together with operating elements therein, are held in assembled relation by a cover I I of sheet metal spun over the nose as at I2 and over the shoulder at it.

v The member ill carries the usual booster charge is with a tetryl booster lead I5 connecting therewith. Mounted in a channel It in the body member ID, for sliding movement transversely of the axis of the fuze, is the detonator holder Ii carrying the detonator element l8 that is movable into alignment with booster lead I5 when the fuze is armed. The detonator holder I! is held in unarmed position against stop I9 by spring pressed detents 20 that engage in the hole 2| in the holder I! and which are releasable from engagement with the holder I! by centrifugal ioroe. It will be noted that more than onehalf the mass of the holder I! is on the lefthand side of the axis of the fuze as shown in Fig. 2, and hence when the detents 20 are released the centrifugal force will move holder I! to the left in Fig. 2 and bring the detonator I8 into alignment with booster lead I5. This eliminates the friction between detonator holder I! and detents 2!! that would be present if a spring were used to slide the holder IT.

The body member 9 has mounted in it along its axis the firing pin 22 which has a heavy collar 23 adjacent its inner end or point 24 and a light, readily shearable flange 25 adjacent its outer end. In the unarmed condition the spring pressed detents 26 engage the inner face of collar 23 and positively hold the firing pin 22 in unarmed position. On the outer end of firing pin 22 is the impact head 21 seated against the light flange 25 and retained in position on the firing pin by upsetting the end of the firing pin at 28. If, through accident, the fuze is dropped so that impact head 21 strikes while the bomb is unarmed, the light flange 25 will shear and the impact head will merely slide along the firing pin 22 so that the detonator 88 would not be exploded even though it might fortuitously be aligned with the firing pin and the booster lead I5. When the fuze spins, however, the detents 26 are moved outwardly by centrifugal force and the detonator holder is simultaneously shifted to align the detonator l8 with firing pin 22 and booster lead I5. Firing of the detonator I8 by air pressure on head 21 after the fuze has been armed is prevented by the separator disc 29 disposed between the point 24 of firing pin 22 and the detonator holder I1. However, the separator disc 29 is readily puncturable and ofiers no impediment to firing the detonator I8 when head 21 impacts upon a target with the fuze in armed condition.

While the present invention has been shown and described in connection with a bomb of the spinning type, it is also capable of use in projectiles fired from rifled barrels, of one inch caliber or greater, or in projectiles that are caused by any means to spin during flight.

The invention herein described and claimed in said body to be translationally slidable trans- "versely of the axis of said body and having a comprising a body, a booster charge in said body,

an axially extending booster lead connecting with said booster charge, a detonator holder mounted in said body to be translationally 'slidable 'trans- I versely of the axis of said body and having a detonator therein to be alined with said booster lead when said holder is in thearmed position,-

spring pressed detents engaged with said holder 2 to retain said holder in the unarmed positionbut releasable therefrom by centrifugal force, said holder being moved to armed position by. centrifugal force after release of said detents, a

firing pin disposed along the axis of said body, said pin having a heavy collar adjacent its inner end and a light shearable flange adjacent its outer end, spring pressed detents engaging the inner.

face of said collar to hold said firing pin in unarmed position but releasable therefrom by centrifugal force, an impact firing headsecured on the outer end of said firing pin seated against the outer face of said light flange and adapted to shear said flange in case of impact on said head I when said firing pin is in unarmed position, and a puncturable separator disk between the inner end of said firing plnzand said detonator holder.

2. A fuze armable by rotation about its axis,

' comprising a body, a booster charge in said body,

an axially extending booster lead connecting with said booster charge, adetonator holder mounted in said body to be translationally slidable transversely of the axis of said bodyand having a detonator therein to be alined with said booster lead'when said holder is in the armed position, means engaged with said holder to retain said holder in the unarmed position but releasable therefrom by centrifugal force, said holder being moved to armed position by centrifugal force after release of said means, a firing pin disposed along the axis of said body, said pin having a heavy collar adjacent its inner end and a light shearable flange adjacent its outer end, means engaging the inner face of said collar to hold said firing pin in unarmed position but releasable therefrom by centrifugal force, an impact firing head secured on the outer end of said firing pin seated against the outer face of said light flange and adapted to shear said flange in case of impact on said head when said firing pin is in unarmed position, and a puncturable separator disk between the inner end of said firing pin and said detonator holder.

3. A fuze armable by rotation about its axis, comprising a body, a booster charge in said body, an axially extending booster lead connecting with said booster charge, a detonator holder mounted after release of saidmeans, a firing pin disposed I i detonator therein to be alined with said booster lead when said holder is in the armed position,

springpresseddetents engaged with said holder I I to retain said holder in the unarmed position but releasable therefrom by centrifugal force, said holder being moved to armed position by cen-' trifugal force after release of' said detents, a firing pin disposed along the axis of said body, I said pin having a heavy'c'ollar adjacent its inner I end, spring pressed detentsiengaging the inner face of :said collar to hold said firing pin in unarmed position but releasable therefrom by cen- I trifugal force, an impact firing head secured on the outer end of said firing pin, and means operably connecting said'impact head to said firing pin,said connecting means being shearable in case of impact on said head before said detents are disengaged from said heavy'flange.

4. A fuze armable' by rotation about its axis, comprising a body, a booster charge in said body, an axially extending booster lead connecting with said booster charge, a detonatorholder mounted in said body to be translationally slidable transversely of the axis of saidbody and having a detonator therein to be alined with said booster lead when said holder is in the armed position,

means engaged with said holder to retain said holder in the unarmedposition but releasable therefrom by centrifugal force, said holder being moved to armedposition by centrifugal force along the axis of said body, means engaging said firing pinto hold said firingpin in unarmed position but releasable therefrom by centrifugal force, i d

an impact firing head secured on theouter end of'said firing pin, and means operably connecting said impact head to said firing pin, said connecting means being shearable in case of impact on said head before said firing pin engaging means is released.

RAYMOND L. GRAUMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 15,882 Schlafer July 29, 1924 1,172,636 Semple Feb. 22, 1916 1,306,664 Hawken June 10, 1919 1,309,500 Wildrick July 8, 1919 1,563,418 Adelman Dec. 1, 1925 1,852,951 Auriol Apr. 5, 1932 2,068,708 Reed Jan. 6, 1937 2,085,053 Teitscheid June 29, 1937 FOREIGN PATENTS Number Country Date 257,335 Great Britain Aug. 7, 1926 

